Filter presses are used for dewatering, drying, separation, extraction, chemical processing etc. of a wide range of materials. The material to be processed is held in chambers formed between adjacent filter plates. When processing is complete, the chambers are emptied of any remaining material—for example filter cake remains after a drying process and is removed for further processing. This emptying process requires the filter plates to be physically separated so as to open up the chambers and allow the remaining material to be removed/fall out. Plate shifters are used to separate the plates in the filter plate stack and to restack the filter plates after the chambers are emptied. The emptying process is time consuming and is in need of improvements to reduce the time required to empty the chambers and to restack the filter plates.